Work

Experimental Investigation on Effect of Vegetation Distribution Pattern on Hydraulic Characteristics of Overland Flow

Year: 2025

Type: article

Abstract: ABSTRACT The vegetation distribution pattern is crucial for controlling soil erosion on slopes. However, the effects of varying vegetation column ( b ) and row ( d ) spacings on the hydraulic characteristics remain underexplored. To address this, 216 indoor scour experiments were conducted under controlled variations in b and d (0.01–0.09 m), flow discharge ( Q , 0.3–1.0 L/s) and slope gradient ( θ , 15°–45°). Results showed that overland flow consistently remained in the supercritical transition regime. The flow regime was influenced collectively by b , d , θ and Q . Form resistance dominated the total flow resistance, accounting for more than 80%, and its proportion ( P ) decreased with increasing b or d , but increased with higher θ . Variations in d exerted a greater influence on P than those in b . The flow resistance coefficient ( f ) decreased with increasing b or d , but this effect weakened at higher θ or Q . On gentle slopes, increasing b or d amplified the effect of Re on f , whereas this influence diminished on steeper slopes. The relationships of f with b , d and Re were effectively described by power functions. A predictive model for f , incorporating b , d , Re , θ and grass stem diameter, was developed and showed consistent accuracy across all datasets ( R 2 > 0.820). These results support optimised vegetation designs for effective erosion control.

Source: Hydrological Processes

DOI: 10.1002/hyp.70234